By the latest news from Europe, we learn that the above vessel was successfully launched on Sunday the 31st ult. The final floating of the great iron ship was accomplished with ease and without accident. The mode of launching was the same from first to last in all the trials, but more powerful and more numerous agencies—hydraulic rams, chains, beams, windlasses and levers—had to be finally employed, than was at first calculated upon. Much has been taught by this affair in regard to moving large masses. It was the first ship launched broadside in England, and the greatest mass of overtowering gravity ever attempted to be slid on ways. She was towed to Deptford where she is to remain until all her engines and internal arrangements are completed. We hope she will be a successful steamer, but this hope is expressed against many doubts, because such a large vessel must be very difiicult of management on any element, and because it has been found that the largest steamers, varying from 3000 to 5000 tuns burden do not yield such profitable returns as those varying from 2000 to 2800 tuns.